Introducing: The Weekly DTIC

Small arms science and history are both areas of great interest for me, and the Defense Technical Information Center (DTIC) is the primary source of the historical documents I use to feed this interest. DTIC is a wealth of information on all defense topics, and the information contained there pertaining to small arms seems near-endless. Every week from now on, I will be sharing a document from DTIC that is important to both small arms history and science, here on The Firearm Blog.

To start, I’ll be posting a very technical article, but one that was vital to the development of the modern infantry rifle: The Theory Of The Motion Of A Bullet About Its Center Of Gravity In Dense Media, With Applications To Bullet Design, published by Aberdeen Proving Ground in January of 1930 (three decades before the fruits of its research would reach the hands of US troops). Weaponsman.com, an excellent blog, has covered it previously, which doesn’t at all dull its contents. Beyond its Tolstoy-esque title lies pages of equations describing – among other things – a fundamentally simple principle: When a projectile hits a dense medium, such as water or tissue, it will lose stability and yaw within a proportionally shorter distance than a larger caliber projectile, all other things (such as velocity, projectile shape, and density) being equal. In other words, a .25 caliber projectile identical to a .50 caliber one in every way but size, and moving at the same velocity, will yaw and deposit its energy into a target within half the distance of the larger one.

Upon this principle, the then-nascent concept of small caliber, high velocity ammunition was based, one which has since come to dominate the arena of infantry weapons for half a century and counting.

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He can be reached via email at nathaniel.f@staff.thefirearmblog.com.

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The equations lost me, but the text conveyed the conclusion pretty well. So, is it fair to say that it took the U.S. military 25-30 years to realize the significance of this paper? What about other countries? What round or rounds were first developed after 1930 based on this information?

To fully realize it in the fielding of the AR-15/M16, yes I think that’s true. However, US SCHV experiments did get off the ground earlier; immediate post-war experiments involved the .22 Gustafson, a .222 Remington cartridge shortened to fit in the OAL of an M2 Carbine for trials purposes. Earlier, the Pig Board tests of 1928 were probably the first practical demonstration of this principle, showing that the .256 caliber cartridge tested outperformed in terminal effect both the .276 and .30 caliber test cartridges.

Even earlier, the principle of longer, thinner bullets at higher velocities producing better external ballistics (that is, trajectory, flight time, and wind drift characteristics) was known as far back as the late 1860s. The US, among other countries first discovered this around that time, and the result was the (then small-caliber, high velocity) .45-70 Government round. Eventually, this concept reached its height in the US Army with the .30 Government (eventually maturing into the .30-06 cartridge), a positively magnum round for the era, and saw even more extreme forms with other nations and services, most notable Sweden and the US Navy, with the 6.5×55 Swede and 6mm Lee Navy cartridges, respectively.

The US really led the development of .22 caliber intermediate rounds, despite also being host to the “mafia” that demanded .30 caliber ammunition across all of NATO, led by Colonel Studler. If contemporary experiments as well-grounded as the American post-war ones existed in other nations, I don’t know of them.

I highly recommend you read both “The Black Rifle” by R. Blake Stevens and Edward Ezell, as well as “SPIW: The Deadliest Weapon That Never Was”, by the former. Neither are cheap, but they are a wealth of information on the subject. The groundwork that was laid for our modern weapons occurred mostly in the ’40s and ’50s makes for a fascinating read; the story of SCHV is truly epic in scale and just totally riveting to a small arms nerd like myself, regardless of whether one agrees with the concept or not.

The author of the report, Robert H. Kent, ultimately became Associate Director of the Ballistic Research Laboratories at Aberdeen Proving Ground. The following link includes a brief biography and a partial listing of his publications: